Case-hardened steel.



A. P. SHORE.

I CASE HARDENED STEEL.

I APPLICATION FILED-APB..5,'1913.

1,072,661 v Patented Sept. 9, 1913.

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ALBERT r. SHORE, or NEW YORK, N. Y.

CASE-HARDENED STEEL.

Specification of Letters Patent. Application area April 5, 1913. Seriala... 759,009.

Patented Sept. 9, 1913.

To all whom it may concern:

Be it known that I, ALBERT F. SHORE, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements 'n Case- HardenedSteel, of which the follo ing is a full, clear, and exact specification.

This invention relates to case-hardened steel,,and the object of theinvention is the production of a structure in steel suitable forarmor-plates, large guns, projectiles, or machine elements or partsthereof, and composed of two or.more layers or sections of differentdegrees of hardness and arranged so as to interlock to prevent peelingor flaking.

In my pending application Serial Number 627 ,747, I have described'andclaimed the process for case-hardening steel, the result of whichprocess is the subject of the present application.

In the drawing forming part of this specification, I have illustratedsteel plates characterized by having two layers of different degrees ofhardness and interlocked or so arranged that there is an irregular planeof separation between the layers, and the novel features of the productare pointed out in I the claim.

Figure 1 IS a cross-sectional view of a 7 steel plate embodying myinvention. Figs.

ducing 2, 3, 4:, and 5 illustrate modified forms or arrangements of theinterlocking layers, and

Figs. 6 and 7 illustrate two different means used for carrying "out theprocess for prothe steel plates shown in the other figures.

The process is described in detail in the pending application referredto and embodies the partial covering of the steel plate 6 by a suitablecarbon-resisting agent, such as cement for instance, which may be put onthe plate in the preferred form, as'shown at 7, which leaves uncoveredand therefore unprotected the portions 8 of the plate. Or, as shown inFig. 7, the covering may be in the form of individual disks 9.Thereafter, the plateis carburized to the desired depth at the portions8. 1

The result of the process is illustrated in Fig. 1,- in which 11represent the carburized portions of the plate-and 13 represents the,

softer backing. 12 represent the protected or covered areas on theplate, where the material has also been carburized but to a less degreethan at 11, and, due to the peculiar prevented andcrushing strains orblows localized. v

By making the protective coverin small or narrow, as shown in dottedlines in Fig. 2 at 16, the interlocking Fig. 3 illustrates the resultsobtained ortion 17 of the layer 13 is made quite sma l and pointed.

when the covering 18 is quite broad and only semi-resistant'to carbon.In this instance the interlocking portion 19 is large. Thesemi-resistant may in this instance consist of cement as above, but in amore porous state. I

Fig.v 4 shows the results obtained by employing two narrow coverings 20,close to one another. In this instance the interlockadjacent pointed andwhereby the interlocking portion 24 becomes large with an irregular lineof separation between it and the layer 11.

It will be apparent that in each of the in- I stances illustrated I haveproduced a unitary steel plate composed of two sections or layers ofdifferent degrees of hardness having an irregular plane of separationbetween them and whereby each section is formed with interlockingportions extending beyond or inside the area of the adjacent section. a

I claim; I

As a new article of manufacture, a unitary steel plate consisting of asingle integral piece of material comprising a bod; portion In testimonywhereof, I affix my signaand a face portion, said face portion beingture, in presence of two witnesses, of greater hardness and lessthickness than the said body portion, both of said portions ALBERT'F' O5 ofthe single piece of material having regu- Witnesses:

larly formed interlocking spaced portions MARTHA W. SHAW,

extending into each other. CHAS. BEIMAR.

